PF1963 Prenyltransferase that catalyzes the transfer of the geranylgeranyl moiety of geranylgeranyl diphosphate (GGPP) to the C2 hydroxyl of (S)-3-O-geranylgeranylglyceryl phosphate (GGGP). This reaction is the second ether-bond-formation step in the biosynthesis of archaeal membrane lipids (By similarity). (S)-2,3-di-O-geranylgeranylglyceryl phosphate synthase PF1963 Digeranylgeranylglyceryl phosphate synthase DGGGP_PYRFU MEVKGFIEIMRPHNCILAGIVGILGALVAYEGIPDIKTLTLIFWVVYFGCSGGNTANDYFDYEIDKINRPNRPLPRGAMSRRAALYYALLQYAIGSILAYFLNIRAFVFATIAYFLTFLYGWKLKPLPLVGNITVAALTAATPIYGAIGVGRIGLAGYLAICAFLVNVSREIMKDIEDIEGDKALGARTLPIIIGEKKAAIIAAIFGFLTVIASFLPVKVGIGLGYAPIIIVDIIIIKASIDVLRDPKAASKGQKLLKIATFVAVISFLAGALTKGV 277 Geranylgeranylglycerol-phosphate geranylgeranyltransferase